P ocedia Enginee ing 100 ( 2015 ) 1232 – 1241
1877-7058 © 2015 The Au ho s. Published by Else ie L d. This is an open access a icle unde he CC BY-NC-ND license
(h p://c ea i ecommons.o g/licenses/by-nc-nd/4.0/).
Pee - e iew unde esponsibili y o DAAAM In e na ional Vienna
doi: 10.1016/j.p oeng.2015.01.488
ScienceDi ec
A ailable online a www.sciencedi ec .com
25 h DAAAM In e na ional Symposium on In elligen Manu ac u ing and Au oma ion, DAAAM
2014
S udy o Ma e ials P oduced by Powde Me allu gy Using Classical
and Mode n Addi i e Lase Technology
Jose Sedlaka
*
, Daniel Ricana, Mi osla Piskaa, Lubos Rozkosnyb
aB no Uni e si y o Technology, Facul y o Mechanical Enginee ing, Technicka 2, 616 69 B no, Czech Republic
bInnomia a.s., Huso a 114, 551 01 Ja ome , Czech Republic
Abs ac
The pape ocuses on an analysis o ma e ials p oduced by mode n classic addi i e me hod di ec me al lase sin e ing (i.e.
powde me allu gy). Di ec me al lase sin e ing belongs o ile o addi i e echnologies o apid p o o yping. Rapid p o o yping
echnology is a p og essi e g oup o me hods used o as c ea ing o models, p o o ypes and componen s di ec ly om 3D da a.
Acco ding o a used echnology pho opolyme s, he moplas ics, specially modi ied pape o me al powde s a e used in apid
p o o yping machines. Nowadays hose p oduc ion machines c ea es no only models and p o o ypes, bu hey a e used o
manu ac u e ools, o ms and componen s o small se ies p oduc ion.
The pu pose o he heo e ical pa is o gain in dep h unde s anding o exac ly wha is he p inciple o di ec me al lase sin e ing
and wha a e p ope ies o explo ed ma e ials. The p ac ical pa analyses s uc u es o ma e ials used by classic and powde
me allu gy. I concen a es on samples p epa a ion, hei analysis (using ligh and elec on mic oscopy) and es ing. Samples a e
analysed by mechanical ensile es and Vicke s ha dness es . The pape also compa es sin e ed samples wi h s eel equi alen s
p oduced by classic me allu gy gi ing inal ecommenda ion.
© 2015 The Au ho s. Published by Else ie L d.
Pee - e iew unde esponsibili y o DAAAM In e na ional Vienna.
Keywo ds: Rapid P o o yping; Di ec Me al Lase Sin e ing; Manu ac u ing Machine; Me allog aphic Analysis; Mechanical P ope ies
* Co esponding au ho . Tel.: +420 541 142 408; ax: +420 541 142 402.
E-mail add ess: sedlak@ me. u b .cz
© 2015 The Au ho s. Published by Else ie L d. This is an open access a icle unde he CC BY-NC-ND license
(h p://c ea i ecommons.o g/licenses/by-nc-nd/4.0/).
Pee - e iew unde esponsibili y o DAAAM In e na ional Vienna
1233
Jose Sedlak e al. / P ocedia Enginee ing 100 ( 2015 ) 1232 – 1241
1. In oduc ion
DMLS is a e olu iona y RP addi i e me hod. Which is becoming mo e a mo e impo an and nowadays i is
conside ed o be he mos pe spec i e me hod o as ins umen applica ions. The me hod has s ill been de eloping.
Cu en ly his manu ac u ing machine is able o di ec ly sin e me al powde s (i.e. powde s which a e no co e ed
wi h a plas ic o o he ma e ial wi h low mel ing poin ). Laye s o s anda d me al powde s wi h a low mel ing poin
con ain phospho us ha is ha m ul o mos o me als e en in small quan i y. The e o e he e exis ela i ely ha d
cons uc ion limi s. Ma e ial quali ies a e om now on a limi ing ac o o sp ead his me hod. A ange and quali ies
o a ailable ma e ials ha e s ill been imp o ing [1, 2, 3, 4, 5, 6, 7].
A p inciple o addi i e me hod DMLS Fig. 1 is based on he g adual mel ing o ul a-line laye s o me al powde
using a lase beam. A p oduc ion o p o o ype componen s a s by p e-p ocessing when a machinis load STL da a
o a model o so wa e o manu ac u ing machine EOSINT M 270. So wa e designed o p epa a ion o da a o
manu ac u ing machine EOSINT M 270 is e y easy. I enables easily and quickly con ol alidi y o inpu da a and
wi h help o clea g aphics in e ace i is possible o de ine loca ion in wo king space, suppo ype e c. The nex s ep
is a choice o building powde ma e ial and app op ia e hickness o manu ac u ing laye s conside ing
p ecision/ esolu ion and manu ac u ing speed. The se ice so wa e assigns igh echnology pa ame e s o building
and “cu “ 3D da a in o componen laye s. Da a a e subsequen ly sen o he manu ac u ing machine EOSINT M 270.
A s eel pla o m is ixed o a wo king chambe o manu ac u ing machine. The componen is buil on he s eel
pla o m a ba ching plan se s needed powde amoun o one laye and a li a m wi h a ce amic edge sp eads a
uni o m laye s on su ace o s s eel pla o m acco ding o he se hickness. Con ol so wa e o manu ac u ing
machine con ols a iable ocusing o a lase beam and a beam ajec o y along componen ou line. The me al
powde is o ally mel ed in he place o he lase beam all whe e a bo om laye is “mel ed h ow-ou ” and
subsequen ly i solidi ies [2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13].
The pape goal is o e i y i powde ma e ials (co osion esis an s eel EOS GP1, ma ensi ic s eel EOS MS1)
p ocessed by addi i e me hod DMLS a e hei mechanical p ope ies ully compa able o ma e ials p oduced by
classic con en ional echnologies. Tes ing samples a e p oduced by manu ac u ing machine EOSINT M 270 wi hin
an analysis. They a e chip machined, analysed (ligh and elec on mic oscopy), es ed (mechanical ensile es and
Vicke s ha dness es ) and compa ed wi h s eel equi alen s - X5C NiCuNb16-4 (1.4542), X3NiCoMoTi18-9-5
(1.2709) p oduced by classical me allu gy.
Fig. 1. P inciple o DMLS Me hod [3, 14].
1234 Jose Sedlak e al. / P ocedia Enginee ing 100 ( 2015 ) 1232 – 1241
2. Expe imen
The p ac ical pa p esen s ma e ial analyses and shows esul s o se e al mechanical es s. Analysed ma e ials
a e GP1 EOS, EOS MS1 o EOSINT sys ems and ma e ials X5C NiCuNb16-4 (1.4542) X3NiCoMoTi18-9-5
(1.2709) p oduced by con en ional me allu gy.
2.1. Desc ip ion o Analysed Ma e ials
S ainless S eel GP1 is alloyed s ainless s eel in he o m o a ine powde . The chemical composi ion co esponds
wi h he U.S. classi ica ion 17-4 PH and Eu opean classi ica ion 1.4542. This s eel ype is cha ac e ized by e y
good co osion esis ance and good mechanical p ope ies especially excellen duc ili y. Chemical composi ion o
s eel is desc ibed in Table 1.
Table 1. Chemical Composi ion o S eel [Weigh %] [15, 16].
C
Si
Mn
Mo
Ni, Cu
C
Nb
Max. 0.07
Max. 1.00
Max. 1.00
Max. 0.50
3.00 – 5.00
15.00 – 17.50
0.15 – 0.45
Co osion- esis an s eel X5C NiCuNb16-4 is a ma ensi ic p ecipi a ion ha dening s eel s abilized by niobium
(Nb). The excellen co osion esis an o s eel is compa able o co osion esis ance o aus eni ic s eel. When he
s eel is hea ed i is esis an o in e g anula co osion and e osion in co osi e en i onmen as well. Chemical
composi ion o s eel is in Table 2.
Table 2. Chemical Composi ion o S eel [Weigh %] [17].
C
Si
Mn
P
S
Mo
Ni, Cu
C
Nb
Max. 0.07
Max. 0.70
Max. 1.50
Max. 0.040
Max. 0.015
Max. 0.60
3.00 – 5.00
15.00 – 17.00
5 imes C
up o 0.45
MS1 Tool s eel appea s in he o m o a s eel powde . I s composi ion co esponds wi h he Eu opean
classi ica ion 1.2709 and Ge man classi ica ion X3NiCoMoTi 18-9-512. I has excellen mechanical p ope ies.
Hea ea men is e y easy. When s eel is simply hea -ha dened (ha dening a 490°C o 6 hou s) i ecei es high
ha dness and s abili y. Chemical composi ion o s eel is in Table 3.
Table 3. Chemical composi ion o S eel [Weigh %] [15, 16].
C
Si, Mn
P, S
C
Mo
Co
Ni
Ti
Max. 0.03
Max. 0.15
Max. 0.010
Max. 0.50
4.50 – 5.20
8.50 – 9.50
17.00 – 19.00
0.60 – 0.80
Tool s eel X3NiCoMoTi18-9-5 is high-s eng h ma ensi ic s ainless s eel sui able o wo k unde ex eme cold
and ho empe a u es. The e o e ool s eel is app op ia e o highly s essed componen s o ae onau ics indus y and
ocke echnologies, p essu e essels, gea s, moulds o plas ic manu ac u ing and ools o p essu e cas ing.
Chemical composi ion o s eel is in Table 4.
Table 4. Chemical composi ion o he s eel [Weigh %] [17].
C
Si, P, S
C
Mo
Co
Ni
Ti
Max. 0.03
Max. 0.10
Max. 0.25
4.50 – 5.20
8.50 – 10.00
17.00 – 19.00
0.80 – 1.20
3. Tes s o Mechanical P ope ies
Tensile es and Vicke s ha dness es we e ca ied ou o indica e mechanical p ope ies.
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Jose Sedlak e al. / P ocedia Enginee ing 100 ( 2015 ) 1232 – 1241
3.1. Tensile Tes
Uniaxial ensile es o ma e ials belongs o basic es s. I is p e-de e mined o become he mos widesp ead and
accep ed es ing me hod o e alua ing he mechanical p ope ies o ma e ials. All because o i s p inciple o
simplici y and unc ionali y [18, 19]. Tensile es was ca ied ou acco ding o IEC 10002, ISO 6892-1 and DIN
50 128.
The compa ison o EOS GP1 ma e ial p oduced by DMLS me hod wi h ma e ial X5C NiCuNb16-4 (1.4542)
p oduced by con en ional me allu gy is shown in Table 5 and Fig. 2. Cu es o ensile diag ams show ha he
ma e ial GP1 exhibi s especially highe ensile s eng h abou 400 MPa. Yield s eng h is almos 400 MPa lowe .
Con ac ion is 45% lowe , elonga ion alues a e iden ical.
Table 5. Measu ed Values – Ma e ial 1.4542 and GP1.
Ma e ial
S0 [mm2]
Rp0.2 [MPa]
Fmax [N]
Rm [MPa]
A [%]
Z [%]
GP1
28.18
564.29
41,906.96
1,489.10
11.69
15.67
1.4542
28.18
1,019.86
29,659.79
1,068.05
10.91
62.55
Fig. 2. Nominal Tensile S esses o Tes ed Ma e ials (1.4542, GP1).
The compa ison o ma e ial MS1 p oduced by DMLS me hod wi h ma e ial 1.2709 p oduced by con en ional
me allu gy is shown in Table 6 and Fig. 3. The ensile diag am cu es show ma e ial MS1 exhibi ing highe alues
o examined pa ame e s han ma e ial 1.2709 ( he ensile s eng h is abou 200 MPa highe and he yield s eng h is
abou 70 MPa highe ). Con ac ions a e 25% highe , elonga ion alues a e almos iden ical.
Table 6. Measu ed Values – Ma e ial 1.2709 and MS1.
Ma e ial
S0 [mm2]
Rp0.2 [MPa]
Fmax [N]
Rm [MPa]
A [%]
Z [%]
MS1
28.18
901.94
35,903.61
1,274.51
14.28
49.37
1.2709
28.18
833.32
29,634.91
1,050.84
15.35
74.42
1236 Jose Sedlak e al. / P ocedia Enginee ing 100 ( 2015 ) 1232 – 1241
Fig. 3. Nominal Tensile S esses o Tes ed Ma e ials (1.2709, MS1).
4. Vicke s Ha dness Tes
Ha dness measu emen was p ocessed acco ding o he s anda d ISO 6507 [18, 19]. I was ca ied ou unde oom
empe a u e (20 ± 5°C). The load es ing was done o 10 HV.
The ha dness compa ison o ma e ials GP1 and MS1 made by DMLS wi h ma e ials p oduced in a s anda d way
is shown in Fig. 4 and Fig. 5.
The g aph compa ing ma e ials GP1 and 1.4542 shows isible inc ease o ha dness in de o med (s eng hened)
sample pa o GP1 ma e ial in compa ison wi h he sample o ma e ial 1.4542, whe eas ha dness alues a e almos
cons an h oughou he whole sample leng h. To de e mine ac ual sample ha dness i is impo an o ocus on he
undis o ed sample pa whe e ha dness alues o GP1 ma e ial is abou 60 HV highe .
Fig. 4. Compa ison o Ha dness (HV 10) Values o Ma e ials GP1 and 1.4542.
The compa ison o ma e ials MS1 wi h 1.2709 indica es ha ha dness alues a e almos cons an h oughou he
sample o bo h ma e ials. Ye o de e mine ac ual ha dness, alues a e compa ed in he undis o ed head o es
sample whe eas MS1 ma e ial ha dness is abou 60 HV highe .
Fig. 5. Compa ison o Ha dness (HV 10) Values o Ma e ials MS1 and 1.2709.
150
200
250
300
350
400
450
500
550
12345678910
Numbe o me asu eme n [-]
Ha dness [HV 10]
GP1 1.4542
150
200
250
300
350
400
450
12345678910
Numbe o measu emen [-]
Ha dness [HV 10]
MS1 1.2709

1237
Jose Sedlak e al. / P ocedia Enginee ing 100 ( 2015 ) 1232 – 1241
5. Me allog aphic Analyses
Fo explo a ion and eco ding o ma e ials s uc u es he ligh mic oscope Olympus GX 51 wi h digi al came a
and he scanning elec on mic oscope Philips X L30 a e used. The me allog aphic analysis compa es s uc u es o
explo ed ma e ials. I compa es ma e ials mic og aphs om ligh and elec on mic oscopy. Fig. 6 a), b) shows a
e i ic-pea li ic mic os uc u e whe e e i e pa ially shows Widmanns a en mo phology. The s uc u e in Fig. 7 a),
b) is made o ma ensi e and pea li e [2, 20, 21].
Fig. 6 (a) Mic og aph o Ma e ial 1.2709 (Ma ble); (b) Mic og aph o Ma e ial EOS MS1 (Ma ble).
Fig. 7. (a) Mic og aph o Ma e ial 1.2709 (Ma ble); (b) Mic og aph o Ma e ial EOS MS1 (Ma ble).
Fig. 8 a), b) and Fig. 9 a), b) show he ma ensi ic s uc u e and esidual aus eni e.
Fig. 8. (a) Mic og aph o Ma e ial 1.4542 (Ma ble); (b) Mic og aph o Ma e ial EOS GP1 (Ma ble).
1238 Jose Sedlak e al. / P ocedia Enginee ing 100 ( 2015 ) 1232 – 1241
Fig. 9. (a) Mic og aph o Ma e ial 1.4542 (Ma ble); (b) Mic og aph o Ma e ial EOS GP1 (Ma ble).
6. Image Analysis
An image analysis is done in images gained by ligh mic oscopy. Po osi y is explo ed on EOS GP1 and EOS
MS1 ma e ials. An analysis o po osi y is ca ied ou by PMG 3 ligh mic oscope wi h DP 20 digi al came a using
S eam Mo ion so wa e. Fields o iew a e pho og aphed o analyze po osi y see Fig. 10 a) and Fig. 10 b). Final
alues o indi idual ields a e shown in Table 7.
Fig. 10. (a) Analyzed a ea – Ma e ial EOS GP1; (b) Analyzed a ea – Ma e ial EOS MS1.
Table 7. Final Pa ame e s and Po osi y o Analyzed Ma e ials – GP1, MS1.
Ma e ial
Cu
Shape Fac o [-]
Ve ical
Elonga ion
[-]
Ho izon al
Elonga ion
[-]
Ra io o max.
o min. dimension [-]
GP1
Longi udinal
0.81
0.36
2.24
1.91
Pe pendicula
0.79
0.37
2.05
1.81
MS1
Longi udinal
0.68
0.38
2.16
1.86
Pe pendicula
0.90
0.45
1.87
1.66
Ma e ial
Cu
Maximum Diame e
A e age Dimension
A ea
Po osi y
1239
Jose Sedlak e al. / P ocedia Enginee ing 100 ( 2015 ) 1232 – 1241
[μm]
[μm]
[μm2]
[%]
GP1
Longi udinal
12.06
7.74
3,863.52
0.05
Pe pendicula
10.41
6.75
3,972.41
0.05
MS1
Longi udinal
15.69
10.37
16,824.39
0.45
Pe pendicula
12.78
8.60
22,573.05
0.38
The po es shape has signi ican in luence on s ess concen a ion and s ess ise s. Po es in he s uc u e mainly
ha e sphe e shape. The e o e he e a e ewe s ess concen a o s and s ess ise s in he o al olume. Po osi y does
no show any di ec e ec caused by deposi ion and mel ing o indi idual laye s. Po osi y appea s a e y low le els
in he same alues o bo h e ical and ho izon al di ec ion. I can be assumed ha e en his low po osi y should
ha e a nega i e e ec on mechanical p ope ies as Rm, Rp0.2, A. Howe e ensile es s o ma e ials do no con i m
his ac . The compa ison wi h ma e ials 1.4542 and 1.2709 p oduced by s anda d echnology (i.e. olling) shows
highe alues o Rm, Rp0.2. Elonga ion almos co esponds only yield s eng h o GP1 ma e ial is lowe . In conclusion,
po osi y o ma e ials GP1 and MS1 made by DMLS does no ha e a majo impac on mechanical p ope ies [22].
7. Discussion on Expe imen al Resul s
Final indi idual pa ame e s om mechanical es s o ma e ials (co osion- esis an s eel 1.4542 and ool s eel
1.2709 p oduced by s anda d me allu gy and ma e ials EOS GP1 and EOS MS1 made by DMLS) indica e ha
mechanical p ope ies co espond o ma e ial shee s. I is impo an o no e ha ma e ials a e no a e hea ea men .
Re e ences indica e ma e ials 1.4542 and 1.2709 as chemical equi alen s o sin e ed ma e ials EOS GP1 and EOS
MS1 [2, 14, 15].
The compa ison o ensile es esul s wi h Vicke s ha dness esul s shows ha mechanical alues o ma e ials
p oduced by DMLS a e highe han alues o he 1.4542 and 1.2709 ma e ials. I indica es ha ma e ials p oduced
by con en ional me allu gy a e only he chemical equi alen wi h di e en mechanical p ope ies. Fo example
yield s eng h o EOS GP1 ma e ial is abou 400 MPa highe and slip limi is abou 400 MPa lowe compa ed o
1.4542 ma e ial.
The me allog aphic analysis shows a simila mic og aph o analysed samples. Ma e ials p oduced by DMLS
show an inc eased numbe o c acks and discon inui ies o complex impu i ies in compa ison wi h con en ional
ma e ials.
Po osi y o ma e ials EOS GP1 and EOS MS1 is analysed as well. Po osi y o he ma e ials p oduced by s anda d
echnologies canno be moni o ed because hey a e olled ma e ials in which po osi y does no occu . Po osi y
alues o EOS GP1 ma e ial a y in hund ed hs o pe cen o a ea cu and o EOS MS1 ma e ial in en hs o pe cen
o a ea cu .
Conclusion
Analysis and compa ison o pa icula ma e ial s uc u es o classic and powde me allu gy shows ollowing
pa ial conclusions:
x Resul s o ensile es indica e ha pa ame e s (Rm, Rp0,2, A, Z) o ma e ials p oduced by addi i e me hod DMLS
a e no he same as pa ame e s o ma e ials p oduced by classic me hods. Some pa ame e s a e highe , e.g. Rm
alue o ma e ial EOS GP1 is 400 MPa highe and opposi ely Rp0,2 alue is 400 MPa lowe .
x Vicke s ha dness es shows ha ha dness alues o ma e ials p oduced by addi i e me hod DMLS a e 60 HV
highe han alues o classic ma e ials. Measu ed a e age ha dness o EOS GP1 is 428 HV and o EOS MS1 is
394 HV.
x The same phases o ine-g ained ma ensi e and esidual aus eni e a e loca ed in s uc u es o ma e ial EOS GP1
p oduced by bo h classic and addi i e me hod DMLS. A mic os uc u e o ma e ial EOS MS1 is o med by
ma ensi e and pe li e whe e ma e ial 1.2709 is o med by e i e-pea li e mic os uc u e.
1240 Jose Sedlak e al. / P ocedia Enginee ing 100 ( 2015 ) 1232 – 1241
x When addi i e me hod DMLS is applied po osi y o ma e ial EOS GP1 a ies in hund ed hs o pe cen and o
ma e ial EOS MS1 a ies in en hs o pe cen . They a e mos ly sphe ical po es b inging no c imped e ec s oo
ma e ial olume. Tha claim con i m abo e men ioned pe o med mechanical es s.
x Pe o med analyses indica e ha es ing samples p oduced by addi i e me hod DMLS do no con ain almos no
po es and inclusions bu he e exis some excep ions.
x Samples p oduced by addi i e me hod DMLS show huge amoun o dis up ions and complex di compa ing o
samples p oduced by classic me allu gy.
x B eaking mo phology o bo h ma e ials is he same. I assigns quasi- issile cha ac e wi h ansc ys alic b eak
co esponding o analysed mic os uc u es.
Pe o med analyses con i m ha mechanical p ope ies o powde ma e ials EOS GP1 and EOS MS1 p ocessed
by addi i e me hod DMLS a e ully compa able wi h ma e ials p oduced by classic me allu gy. Ca ied es s p o e
ha a p oduc ion o p o o ypes o o he componen s is ully eplaceable by mode n addi i e me hod DMLS.
DMLS me hod p o ides a wide applica ion ange o a ious quali ies, om con olled po osi y o bleeding o
il a ion up o ully homogenous s uc u es ha a e able o each highe solidi y han cas s and o ged pieces.
Table 8 shows summa y e alua ion and compa ison o speci ic pa ame e s o es ed ma e ials.
Table 8. Mechanical P ope ies o Ma e ial S uc u es in Classic and Powde Me allu gy.
Ma e ial
Rp0,2
[MPa]
Rm
[MPa]
A
[%]
Z
[%]
HV 10
[%]
Po osi y
[%]
MS1
901.94
1,274.51
14.28
49.37
394
0.41
1.2709
833.32
1,050.84
15.35
74.42
328
0
GP1
564.29
1,489.10
11.69
15.67
428
0.05
1.4542
1,019.86
1,068.05
10.91
62.55
320
0
In conclusion addi i e me hod DMLS is wo h o be u he and de ailed analysed. The objec o u he analysis
would be compa ison o gi en ma e ials a e hea p ocessing whe e in e es ing mic os uc u es and mechanical
p ope ies a e an icipa ed conside ing a de elopmen o new ma e ials. The use o new o imp o ed plas ic and
me al ma e ials (e.g. wi h highe esis ance, elas ici y o solidi y) ha would lead o sp eading his p oduc ion
me hod is an icipa ed in u u e. Gained esul s men ioned in he pape may in u u e help sp eading addi i e me hod
DMLS in o awa eness o wide public no only in Czech Republic.
Acknowledgemen s
This esea ch was suppo ed and co- inanced by he p ojec Excellen Young Scien is s om B no Uni e si y o
Technology - egis a ion numbe CZ.1.07/2.3.00/30.0039.
Re e ences
[1] Rozkosny, L. Con o ming Cooling o Injec ion Moulding Fo ms. [Online]. 2008. [seen 18 h Decembe 2013]. A ailable a :
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